{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2017:7SCHZAOIBS4BQGF763IVDCCN3W","short_pith_number":"pith:7SCHZAOI","canonical_record":{"source":{"id":"1711.04141","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2017-11-11T14:19:50Z","cross_cats_sorted":["math.IT"],"title_canon_sha256":"51f815ece0634d46a186a8f769f77beac348b9b6737437c5dc1786972a00ca24","abstract_canon_sha256":"260952d7e5473f22b133f04a2d78b586e9aced5a3a9281bd16b73bd45a3ef5ed"},"schema_version":"1.0"},"canonical_sha256":"fc847c81c80cb81818bff6d151884ddda10fce756b7c05b8897ed25176f1d07f","source":{"kind":"arxiv","id":"1711.04141","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1711.04141","created_at":"2026-05-18T00:30:39Z"},{"alias_kind":"arxiv_version","alias_value":"1711.04141v1","created_at":"2026-05-18T00:30:39Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1711.04141","created_at":"2026-05-18T00:30:39Z"},{"alias_kind":"pith_short_12","alias_value":"7SCHZAOIBS4B","created_at":"2026-05-18T12:31:05Z"},{"alias_kind":"pith_short_16","alias_value":"7SCHZAOIBS4BQGF7","created_at":"2026-05-18T12:31:05Z"},{"alias_kind":"pith_short_8","alias_value":"7SCHZAOI","created_at":"2026-05-18T12:31:05Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2017:7SCHZAOIBS4BQGF763IVDCCN3W","target":"record","payload":{"canonical_record":{"source":{"id":"1711.04141","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2017-11-11T14:19:50Z","cross_cats_sorted":["math.IT"],"title_canon_sha256":"51f815ece0634d46a186a8f769f77beac348b9b6737437c5dc1786972a00ca24","abstract_canon_sha256":"260952d7e5473f22b133f04a2d78b586e9aced5a3a9281bd16b73bd45a3ef5ed"},"schema_version":"1.0"},"canonical_sha256":"fc847c81c80cb81818bff6d151884ddda10fce756b7c05b8897ed25176f1d07f","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T00:30:39.971852Z","signature_b64":"HQenJiTu6VI5n8hNJ7UUzELxffzxB71rgupKWSqQJV/Xf2bqNdM1PDoJma0z6I6pn5lHsth3TOHo8QHLs7EIBg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"fc847c81c80cb81818bff6d151884ddda10fce756b7c05b8897ed25176f1d07f","last_reissued_at":"2026-05-18T00:30:39.971051Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T00:30:39.971051Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1711.04141","source_version":1,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-18T00:30:39Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"svzE+2as92zr9YroQj9Pu18FuuxNcbKy6LvOW/f7Ups19ysJYJLnu9/z/z67s3rERw5ntV3ShlSeGmhrr+zbDA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-30T01:39:49.923967Z"},"content_sha256":"28b43361d6a31f6b67f7dbe57165cf60486c63edf772df9cebd5913330ac4d5a","schema_version":"1.0","event_id":"sha256:28b43361d6a31f6b67f7dbe57165cf60486c63edf772df9cebd5913330ac4d5a"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2017:7SCHZAOIBS4BQGF763IVDCCN3W","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Truncated Polynomial Expansion Downlink Precoders and Uplink Detectors for Massive MIMO","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["math.IT"],"primary_cat":"cs.IT","authors_text":"Andreas Benzin, Antonia Tulino, Giuseppe Caire, Yonatan Shadmi","submitted_at":"2017-11-11T14:19:50Z","abstract_excerpt":"In TDD reciprocity-based massive MIMO it is essential to be able to compute the downlink precoding matrix over all OFDM resource blocks within a small fraction of the uplink-downlink slot duration. Early implementation of massive MIMO are limited to the simple Conjugate Beamforming (ConjBF) precoding method, because of such computation latency limitation. However, it has been widely demonstrated by theoretical analysis and system simulation that Regularized Zero-Forcing (RZF) precoding is generally much more effective than ConjBF for a large but practical number of transmit antennas. In order "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1711.04141","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"},"verdict_id":null},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-18T00:30:39Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"xW52+vroFeculHVeAizOhiQlrW2viw9tFKwDJ2oemaXbEUf9pu8Ii9NDK88yXzI0KKd4kGLW1oF3q9mOiD9iCg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-30T01:39:49.924694Z"},"content_sha256":"1db5d6cecb05f095ff9d8b14b28bf1b9b763d4f1878d297e8435a808a58a9d75","schema_version":"1.0","event_id":"sha256:1db5d6cecb05f095ff9d8b14b28bf1b9b763d4f1878d297e8435a808a58a9d75"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/7SCHZAOIBS4BQGF763IVDCCN3W/bundle.json","state_url":"https://pith.science/pith/7SCHZAOIBS4BQGF763IVDCCN3W/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/7SCHZAOIBS4BQGF763IVDCCN3W/bundle.json","status":"primary"}],"public_keys":[{"key_id":"pith-v1-2026-05","algorithm":"ed25519","format":"raw","public_key_b64":"stVStoiQhXFxp4s2pdzPNoqVNBMojDU/fJ2db5S3CbM=","public_key_hex":"b2d552b68890857171a78b36a5dccf368a953413288c353f7c9d9d6f94b709b3","fingerprint_sha256_b32_first128bits":"RVFV5Z2OI2J3ZUO7ERDEBCYNKS","fingerprint_sha256_hex":"8d4b5ee74e4693bcd1df2446408b0d54","rotates_at":null,"url":"https://pith.science/pith-signing-key.json","notes":"Pith uses this Ed25519 key to sign canonical record SHA-256 digests. Verify with: ed25519_verify(public_key, message=canonical_sha256_bytes, signature=base64decode(signature_b64))."}],"merge_version":"pith-open-graph-merge-v1","built_at":"2026-05-30T01:39:49Z","links":{"resolver":"https://pith.science/pith/7SCHZAOIBS4BQGF763IVDCCN3W","bundle":"https://pith.science/pith/7SCHZAOIBS4BQGF763IVDCCN3W/bundle.json","state":"https://pith.science/pith/7SCHZAOIBS4BQGF763IVDCCN3W/state.json","well_known_bundle":"https://pith.science/.well-known/pith/7SCHZAOIBS4BQGF763IVDCCN3W/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2017:7SCHZAOIBS4BQGF763IVDCCN3W","merge_version":"pith-open-graph-merge-v1","event_count":2,"valid_event_count":2,"invalid_event_count":0,"equivocation_count":0,"current":{"canonical_record":{"metadata":{"abstract_canon_sha256":"260952d7e5473f22b133f04a2d78b586e9aced5a3a9281bd16b73bd45a3ef5ed","cross_cats_sorted":["math.IT"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2017-11-11T14:19:50Z","title_canon_sha256":"51f815ece0634d46a186a8f769f77beac348b9b6737437c5dc1786972a00ca24"},"schema_version":"1.0","source":{"id":"1711.04141","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1711.04141","created_at":"2026-05-18T00:30:39Z"},{"alias_kind":"arxiv_version","alias_value":"1711.04141v1","created_at":"2026-05-18T00:30:39Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1711.04141","created_at":"2026-05-18T00:30:39Z"},{"alias_kind":"pith_short_12","alias_value":"7SCHZAOIBS4B","created_at":"2026-05-18T12:31:05Z"},{"alias_kind":"pith_short_16","alias_value":"7SCHZAOIBS4BQGF7","created_at":"2026-05-18T12:31:05Z"},{"alias_kind":"pith_short_8","alias_value":"7SCHZAOI","created_at":"2026-05-18T12:31:05Z"}],"graph_snapshots":[{"event_id":"sha256:1db5d6cecb05f095ff9d8b14b28bf1b9b763d4f1878d297e8435a808a58a9d75","target":"graph","created_at":"2026-05-18T00:30:39Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"graph_snapshot":{"author_claims":{"count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","strong_count":0},"builder_version":"pith-number-builder-2026-05-17-v1","claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"paper":{"abstract_excerpt":"In TDD reciprocity-based massive MIMO it is essential to be able to compute the downlink precoding matrix over all OFDM resource blocks within a small fraction of the uplink-downlink slot duration. Early implementation of massive MIMO are limited to the simple Conjugate Beamforming (ConjBF) precoding method, because of such computation latency limitation. However, it has been widely demonstrated by theoretical analysis and system simulation that Regularized Zero-Forcing (RZF) precoding is generally much more effective than ConjBF for a large but practical number of transmit antennas. In order ","authors_text":"Andreas Benzin, Antonia Tulino, Giuseppe Caire, Yonatan Shadmi","cross_cats":["math.IT"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2017-11-11T14:19:50Z","title":"Truncated Polynomial Expansion Downlink Precoders and Uplink Detectors for Massive MIMO"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1711.04141","kind":"arxiv","version":1},"verdict":{"created_at":null,"id":null,"model_set":{},"one_line_summary":"","pipeline_version":null,"pith_extraction_headline":"","strongest_claim":"","weakest_assumption":""}},"verdict_id":null}}],"author_attestations":[],"timestamp_anchors":[],"storage_attestations":[],"citation_signatures":[],"replication_records":[],"corrections":[],"mirror_hints":[],"record_created":{"event_id":"sha256:28b43361d6a31f6b67f7dbe57165cf60486c63edf772df9cebd5913330ac4d5a","target":"record","created_at":"2026-05-18T00:30:39Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"attestation_state":"computed","canonical_record":{"metadata":{"abstract_canon_sha256":"260952d7e5473f22b133f04a2d78b586e9aced5a3a9281bd16b73bd45a3ef5ed","cross_cats_sorted":["math.IT"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.IT","submitted_at":"2017-11-11T14:19:50Z","title_canon_sha256":"51f815ece0634d46a186a8f769f77beac348b9b6737437c5dc1786972a00ca24"},"schema_version":"1.0","source":{"id":"1711.04141","kind":"arxiv","version":1}},"canonical_sha256":"fc847c81c80cb81818bff6d151884ddda10fce756b7c05b8897ed25176f1d07f","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"fc847c81c80cb81818bff6d151884ddda10fce756b7c05b8897ed25176f1d07f","first_computed_at":"2026-05-18T00:30:39.971051Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T00:30:39.971051Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"HQenJiTu6VI5n8hNJ7UUzELxffzxB71rgupKWSqQJV/Xf2bqNdM1PDoJma0z6I6pn5lHsth3TOHo8QHLs7EIBg==","signature_status":"signed_v1","signed_at":"2026-05-18T00:30:39.971852Z","signed_message":"canonical_sha256_bytes"},"source_id":"1711.04141","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:28b43361d6a31f6b67f7dbe57165cf60486c63edf772df9cebd5913330ac4d5a","sha256:1db5d6cecb05f095ff9d8b14b28bf1b9b763d4f1878d297e8435a808a58a9d75"],"state_sha256":"63693ca800aee40e124e56a47f8dc9fd084defedd33bc5f9f83056b315d30a70"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"o7F1iEe8byWv4I2Qi7Hm/iy519wWQjcTRQyPJfxmLLbbIFJQeqpBFkfj4ooMnD6b6fCFTmE4q2nWrTSOtbLKDw==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-30T01:39:49.928049Z","bundle_sha256":"eff3c38143bf263bdd0d48dca4e06a2a14063e87cb7ffeb5e7a2ab7281d22c04"}}